Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 160829
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
329 AM EST Thu Feb 16 2017

.SYNOPSIS...
High pressure builds overhead through Friday. A weak cold front will
move through early Sunday. High pressure returns Sunday into early
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Another blustery day...as we remain sandwiched between intensifying
northeastward-moving low pressure over Nova Scotia and broad area of
eastward-moving high pressure over the central CONUS. Gusts
generally up to 30 knots possible through late afternoon before
winds become light. Despite ample sunshine...continued cold air
advection will keep temperatures in the U30s/L40s.

Strong radiational cooling tonight under clear skies and weakening
wind speeds will allow low temperatures to fall into the 20s across
the entire area.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure slides to the south Friday...keeping westerly wind
component through much of the day. This will help temper warming
somewhat. Though, gradual airmass modification will bring
temperatures back near climatological norms. It will certainly feel
warmer...as we won`t be battling the gusty winds of previous days.

Southerly return flow develops late Friday as high pressure slides
to our southeast. Rapid warm-up with highs Saturday 15-20 F above
normal. Despite the anamolous warmth, highs Saturday still 10 F or so
below records.

Weak upper-level disturbance approaches late Saturday into Sunday
morning. Some very light precipitation is possible across Central VA
and perhaps into N VA during this period. All liquid as low
temperatures well above freezing.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
In the wake of the departing southern stream low, a deep
amplified ridge of high pressure will build. This will be the
primary weather feature for Sunday and Monday, providing sunny
skies and anomalously warm temperatures.

Northern stream shortwave energy will flatten the 500 mb ridge
axis somewhat by Tuesday as a frontal system approaches. Cold
advection looks limited, as much of the moisture and forcing
remains confined to the Great Lakes/southern Ontario to New
England/southern Quebec, but temperatures may ease down a few
degrees Tuesday and Wednesday as clouds increase and small PoP
chances surface.


&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
While VFR conditions prevail through Saturday night...gusty NW winds
will continue through this evening. Gusts of ~25-30 knots likely
from early this morning through late this afternoon...before wind
gusts subside by this evening. Relatively light winds Friday
and Saturday.

VFR flight conditions should persist Sunday and Monday under
building high pressure.

&&

.MARINE...
SCA criteria gusts ongoing across much of the waters. Expect an
increase in gust speed after daybreak as mixing commences. Despite
increased mixing depth through the morning...wind field weakens
enough to keep gusts mostly high-end SCA. Made a few slight
adjustments to current SCA headlines to account for most likely
ending time of SCA gusts. Light winds expected Friday and Saturday
with high pressure nearby.

There may be a little burst of wind Sunday in the wake of passing
low pressure. However air temperatures will be substantially warmer
than the 40 degree water, which will prevent mixing. Otherwise
winds will be 10 kt or less under building high pressure.

&&

.FIRE WEATHER...
Conditions may become marginally favorable for an enhanced
threat for the spread of wildfires across central VA for a few
hours during the afternoon...as RH values bottom out between
25-30% with reduced fuel moisture. Limiting factors are winds
and temperatures...as sustained winds across this area expected
to remain near 10 kts (gusts 15-20 kts) with high temperatures
in the lower 40s.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...Winter Weather Advisory until 10 AM EST this morning for
     WVZ501-505.
MARINE...Small Craft Advisory until 1 AM EST Friday for ANZ530>533-
     538>542.
     Small Craft Advisory until 4 AM EST Friday for ANZ534-537-543.
     Small Craft Advisory until 7 PM EST this evening for ANZ535-
     536.

&&

$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...HTS
AVIATION...MSE/HTS
MARINE...MSE/HTS
FIRE WEATHER...MSE



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